Liquid crystal displays are used extensively in cellular telephones, pagers, watches, etc. Such displays are illuminated by light panels referred to as back lighting devices. Conventional devices generally utilize a light source mounted adjacent a plastic light waveguide for containing light from the light source entering the waveguide. Light is extracted from the waveguide by providing a surface that changes the reflective or transmissive characteristics of the waveguide causing light striking the surface to be transmitted out of the waveguide.
These conventional devices suffer from light loss associated with inefficient light coupling with the light source being placed next to the plastic waveguide. In addition, these devices usually have the light extraction surface mounted away from the light exiting surface so that a portion of the light striking the surface is reflected back into the waveguide.
In addition to these and other disadvantages associated with conventional back lighting devices, a differently sized back lighting device must be manufactured for a differently sized application.